Geoffrey Wilkinson | Biography

Geoffrey Wilkinson was born on July 14, 1921, in Yorkshire, England, to Henry and Ruth Crowther Wilkinson. It was an uncle, the owner of a small chemical company in the town of Todmorden, who encouraged Wilkinson's interest in chemistry and had the most influence on his career choice. Wilkinson attended the Todmorden Secondary School and then the Imperial College of Science and Technology at the University of London. Supported by a scholarship, he obtained his B.S. degree in 1941 and his doctorate in 1946.

In 1942, while still a doctoral student, Wilkinson worked with the National Research Council on a joint atomic energy project. His work involved separating the various products of atomic fission reactions from one another so they could be studied and the fission process better understood. In the course of this work Wilkinson developed a new technique, ion-exchange chromatography, which has since proven useful in many chemical analyses. Using this technique, Wilkinson identified a number of new isotopes, atomic species which vary only in the number of neutrons within their nuclei. After World War II, Wilkinson continued his research on nuclear chemistry at the University of California at Berkeley. His work there focused on identifying neutron-deficient isotopes, products of atomic fission that are unstable because they have too few neutrons in their nuclei.

In 1950, Wilkinson moved to the Massachusetts Institute of Technology as a research associate. He had come to the end of what he considered to be his effectiveness in nuclear synthesis research, and began to study the chemical nature of the transition elements. These are the elements found in the center of the periodic table; they often have more than a single stable electrical charge state and unusual magnetic properties. One of Wilkinson's first major breakthroughs was to synthesize a compound in which the transition element nickel was chemically bound to phosphorus within a larger molecule.

Despite his decision to change the focus of his research, it was Wilkinson's expertise as a nuclear chemist that earned him a position as an assistant professor at Harvard University in 1951. It was here that he first deduced the sandwich-type molecular structure. Early in 1952, while preparing to teach an inorganic chemistry course, Wilkinson read about a newly synthesized compound, bicyclopentadienyl iron (a chemical made from an iron atom bonded to two five-carbon rings). The structure proposed seemed unlikely to Wilkinson. Based on theories developed by Linus Pauling, he thought that the key to the structure must lie in the distribution of the so-called pi electrons in the cyclopentadienyl ring. Pauling's work indicated that this ion would have its pi electrons very evenly distributed in rings parallel to the plane of the carbon atoms. Wilkinson realized that a stable structure would result if the iron atom bonded through the pi electrons and was thus held equidistant from all of the carbon atoms in the cyclopentadienyl ring. In bicyclopentadienyl iron this would be possible only by having the iron atom "sandwiched" between the two flat cyclopentadienyl groups.

Along with a colleague, Robert B. Woodward, Wilkinson experimentally proved this novel structure in a few days. Woodward coined the term ferrocene, due to the similarity of the structure to the well-known compound benzene. Wilkinson rapidly adapted the synthesis methods to create a number of other sandwich compounds. For discovering this previously unknown class of chemical structure, Wilkinson shared the 1973 Nobel Prize in chemistry with Ernst Otto Fischer. Fischer had also worked on these compounds, and in presenting the award the committee congratulated both men for creating a new field of chemistry.

During the same period, Wilkinson also pioneered the use of the nuclear magnetic resonance (NMR) technique in chemical analysis. In NMR spectroscopy, chemists study the movement of atoms (most often hydrogen) within a magnetic field; each atom emits a distinct spectral line according to its bond. This technique helped to explain the concept of fluctionality, a theory which states that some chemical species may fluctuate back and forth from one bonding structure to another. This technique has since also found considerable use in medicine, where it is called magnetic resonance imaging or MRI. But despite the widespread recognition of the importance of his work, Harvard University did not offer Wilkinson tenure.

In 1955 Wilkinson returned to the Imperial College of Science and Technology to assume the chair of the inorganic chemistry department. Here he continued his work on transition elements and how they form complexes with organic species through pi electrons. In particular, Wilkinson concentrated on several ways in which transition metal complexes serve as catalysts.

Wilkinson wrote widely, publishing more than four hundred articles on the transition metals and their complexes with organic compounds. He also coauthored two textbooks, and received numerous honors and in addition to the Nobel Prize. Wilkinson married Lise Solver Schau in 1951. They have two daughters.